The present invention relates to a device for adjusting the position of a strap return element of in particular an automobile vehicle safety belt.
In most vehicles, this strip return element is disposed on an anchoring tab fixed to the body of the vehicle at a height suitable for the majority of users of so-called normal size.
However, this height is unsuitable for certain users and in particular persons of small size.
In order to solve this problem, a number of devices are known in the art for adjusting the height of this strap return element.
Thus, for example, a device is known from the document FR.2 484 343 for adjusting the height of an anchoring point of a safety belt in which a slide moves along a screw-threaded support rod in the anchoring adjusting range, said rod being rotatively mounted between the walls of a case fixed to an element of the body of the vehicle. The front side of this slide carries an anchoring member for the belt and its rear side carries an element for preventing rotation of the slide which guides it along the inner wall of the case.
A device is also known from the document FR 2 488 201 for adjusting the height of a return element of a vehicle safety belt comprising an adjusting element carrying the return element with a lock which engages in stop notches of a rectilinear guide, it being possible to disengage the lock by an actuating mechanism.
A device is also known from the document FR. 2 482 539 for adjusting the anchoring point of a safety belt disposed above the shoulder of an occupant of a vehicle, in which the anchoring point is carried by a slideway cursor which is movably mounted in a slideway and is capable of being heldx in position by a catch which cooperates with a series of orifices provided in the slideway.
The document FR. 2 513 887 discloses a device for adjusting the position in height of the upper mount of the shoulder strap of a safety belt. This device comprises a slideway mounted on the body of the vehicle, provided with a guide slot and recesses in which penetrates at least one locking element mounted on a slide which carries the upper mount and is capable of being locked and unlocked by a manual actuating element.
The document FR. 2 543 838 discloses an anchoring device for the upper point of a safety belt, comprising a rail having a plurality of apertures which are in two parts, and a locking lug which can be controlled by an actuating knob. The position of the anchoring point is adjusted by the extraction of the lug from an aperture, the displacement of the slide and the reintroduction of the lug in another aperture.
Lastly, the document FR 2 536 288 discloses a device for adjusting the height of a safety belt for an automobile vehicle consisting of a guiding slideway having two sides, locking openings disposed one above the other, and a carriage movable in the slideway, this carriage carrying a fixing or return member of the belt and including stop elements which are transversely movable relative to the direction of movement of the carriage by means of a knob in opposition to the action of a spring for changing from a locking position to an unlocking position.
However, all these devices have a certain number of drawbacks, in particular as concerns possibilities of adjustment, their relatively complex structure and consequently their relatively high manufacturing and mounting costs.
Furthermore, in most of the known devices, the locking elements are biased to their locking position by resilient means which exert thereon a relatively large maintaining force. This obliges the user who desires to shift the strap return element to exert on the elements for shifting these locking means a relatively large force for shifting the locking means to their retracted position and allow the displacement of the strap return element.